Patients with erectile dysfunction present with the inability to initiate or maintain an erection for satisfactory sexual intercourse. Diagnosis involves taking a detailed history and assessing the nature of the underlying cause of the impotence.
Steps in diagnosis include:-
Assessment of sexual history
There are several approved questionnaires to assess sexual function and the effects of treatments. One of the questionnaires includes the International Index of Erectile Function (IIEF). The patient is asked about their current and past sexual relationships, emotional wellbeing, symptoms of impotence (inability to initiate or maintain the erection), medications used, difficulties in arousal, ejaculation or achieving orgasms and presence or absence of erotic and morning erections.
Assessment of medical history
Details of medical ailments like diabetes, high blood pressure, high blood cholesterol, hormonal disorders, prostate and pelvic disorders or surgeries etc. are assessed.
If psychological causes are suspected
If psychological causes are suspected nature of onset (usually sudden), nature of ejaculation (usually altered) presence of self-stimulated or erotic erections, problems or changes in relationships or major negative life events or psychological events are assessed.
If physical causes are suspected
If physical causes are suspected nature of onset (usually gradual), nature of ejaculation (usually unaltered), normal libido, medical history and ailments, history of operations, radiotherapy, or trauma to pelvis or scrotum or use of medications that may affect erection are assessed. Smoking, high alcohol consumption, use of recreational drugs are also assessed.
Physical examination
This includes a complete examination of the genitals and urinary tract. This is important to exclude conditions such as Peyronie's disease, gonadal anomalies, and retractile foreskin. Endocrine abnormalities and hormonal problems may be suspected if there are changes in testicular size and secondary sexual characteristics. All peripheral pulses and blood pressure is measured to detect narrowing of blood vessels. A rectal examination (Digital Rectal Examination) is performed for patients over age 50 years to detect prostate abnormalities.
Investigations
Suggested investigations by the European Association of Urology include:-
- Blood glucose and lipid profiles for all patients especially if not tested in the past 1 year.
- Total blood testosterone as measured in the morning sample.
- If low testosterone is detected then assessment of follicle stimulating hormone (FSH), luteinising hormone (LH) and Prolactin is prescribed.
- Examination of PSA (Prostate Specific Antigen) for patients with prostate abnormalities.
- Blood urea and electrolytes to detect kidney function.
- Liver function tests to detect hepatic disorders.
- Haemoglobinopathy screen in Afro-Caribbean patients to exclude Sickle cell disease.
- Thyroid function tests.
- Studies to test for nocturnal penile tumescence and rigidity. Normal individuals have five to six erections during sleep, especially during rapid eye movement (REM) sleep. Their absence may indicate a problem with nerve function or blood supply in the penis. This is measured by Nocturnal penile tumescence (NPT).
- Other tests include penile biothesiometry that uses electromagnetic vibration to evaluate sensitivity and nerve function in the glans and shaft of the penis.
- Studies of penile blood vessel abnormalities using Duplex ultrasound cavernous arteries, Intracavernous vasoactive drug injections, Dynamic infusion cavernosography, Arteriography (internal pudendal artery studies) etc. An intracavernous injection test for example involves injecting a synthetic hormone into the penis to increase the blood flow. This can assess the abnormality. If the injection fails to produce an erection it may indicate that there is a problem with the blood supply to the penis. Dynamic Infusion Cavernosometry is a technique in which fluid is pumped into the penis at a known rate and pressure. This helps to detect the vascular pressure within the penis. Corpus Cavernosometry is the measurement of the vascular pressure in the corpus cavernosum.
- A Penile Angiogram allows visualization of the blood circulation in the penis. A Digital Subtraction Angiography acquires images of the blood vessels of the penis digitally. Magnetic resonance angiography is similar to magnetic resonance imaging. Magnetic resonance angiography uses magnetic fields and radio waves to provide detailed images of the blood vessels of the penis.
- Evaluation of psychological disorders.
When to consider referral?
- Presence of endocrinal or hormonal disorders
- Young patients with history of pelvic or genital trauma or injury
- Cardiovascular or nerve disorders leading to impotence
- Penile abnormalities that can be corrected by appropriate surgery
- Complex involvement of psychiatric, cardiovascular, psychosexual or endocrine components
- When requested by the patient or his sexual partner
